Safety lowering device



.March 1955 w. T. HENSHAW SAFETY LOWERING DEVICE 2 Sheets-Sheet 1 Filed July 17, 1951 1N VENTOR ATTORNEY March 1, 1955 w. T. HENSHAW SAFETY LOWERING DEVICE 2 Sheets-Sheet 2 Filed July 17, 1951 INVENTOR ATTORNEY United States Patent SAFETY LOWERING DEVICE William T. Henshaw, Elwood, N. J.

Application July 17, 1951, Serial No. 237,085

2 Claims. (Cl. 254-158) The present invention relates to safety lowering devices, and more particularly provides a compactly encased mechanism which may be fixed at some elevated position, as in an upper story of a building, on the deck of a ship or elsewhere, having connected to it a cable or the like initially wound up on a suitable reel so that a more or less heavy body hung from the free end of the cable can be lowered at a safe rate of speed.

The device may be used for the safe lowering of any of a wide range of bodies and objects. Thus, the device may be used as a fire escape for lowering persons safely to the ground from the upper stories of buildings in case of fire or other emergency. It is equally adapted to be used for the lowering of inanimate objects, such as heavy machinery, large pieces of furniture, bales of merchandise and the like, and if built on a somewhat larger scale so as to have increased weight capacity, the device may be hung from davits on the boat deck of a ship and used to lower lifeboats.

Other uses of embodiments of the inventive principles will occur to those skilled in the art and need not be elaborated in this application for Letters Patent, which is concerned more with the structure than with the wide range of uses thereof.

Broadly speaking, the invention includes a casing containing mechanism which is driven by torque applied to a shaft by the weight of the object being lowered, with resistance applied to the mechanism so as to retard its rate of movement and consequently the rate at which the object descends under the force of gravity.

Particular objects of the invention are concerned with improving the simplicity, durability and reliabil1ty of the retarding mechanism, with facilitating the mounting of the device at the elevated location where it will normally be positioned, with providing effective guide means for insuring proper unwinding of the cable regardless of the angular direction from which the unwinding force may be applied and of the angle or inclination at which the encased mechanism may be mounted, and, in certain modified'embodiments of the invention, with regulating the resistance and consequently the speed of descent.

Other objects and advantages will be more apparent as the description of certain preferred embodiments of the invention proceeds.

In the accompanying drawings, which illustrate the presently preferred embodiments,

Figure 1 is a perspective view of the device;

Fig. 2 is a side elevational view thereof;

Fig. 3 is a horizontal cross sectional view taken along the line 3-3 of Fig. 2;

Fig. 4 is a lengthwise sectional view taken substantially centrally through the device, along the line 4-4 of Fig. 2;

Fig. 5 is a lengthwise sectional vlew taken off center of the device along the line 5-5 of Fig. 2;

Fig. 6 is a lengthwise sectional view taken at a right angle to the parallel planes on which Figs. 4 and 5 are taken, i. e., along the axis of the drive shaft, along the line 66 of Fig. 3;

Fig. 7 is a transverse sectional view taken along the line 77 of Fig. 6; and

Fig. 8 is a detail lengthwise sectional view showing a modification.

Referring now to these drawings, Fig. 1 shows at 10 a casing of special shape as illustrated, conveniently made in two similar halves 11 and 12, constitutmg respectively upper and lower portions of; the casing,

.WlJlCh are securely bolted together in fluid-tight relationship by bolts 13.

The casing is hollowed out, as by coring the castings of which the two halves are made, to provide a pair of machined cylinders 14 in the upper half and a pair of similar cylinders 15 in the lower half. The arrangement is such that each upper cylinder is directly opposed to one of the lower cylinders, so that at each side of the casing there are two axially aligned cylinders 14 and 15.

In each of the four cylinders a piston 16 is mounted for reciprocating movement. Each piston may be substantially solid and it is desirable, although not necessary for embodiment of the broad principles of the invention, to seat a coil spring 17 in a socket formed in the outer end of each piston, interposed between the piston and the outer end wall of the casing which closes the cylinder, i. e., between each piston and the bead of the cylinder in which it is mounted. The usual piston rings 18 may be used for packing the pistons, and hardened face or follower plates 19 may be inserted in the inner ends of the pistons.

A drive shaft 20 is journaled in the outer walls of the casing at its transverse center, passing through a center bearing 21 in the solid metal of the casing between the pairs of aligned cylinders.

The shaft 20 has fixed on it a pair of eccentrics or cams 22, one axially aligned with each pair of opposed pistons and bearing against the follower plates 19 thereof by force of the springs 17. The two eccentrics are preferably fixed out of phase, as for example at the displacement best shown in Fig. 5.

it will be evident that when the shaft is rotated the pistons of each opposed pair will be reciprocated in their cyl nders, having a stroke of substantially the length indicated in Fig. 5, in which the upper piston is shown at its extreme cylinder head position and the lower piston is shown at its extreme inner position.

As is also best shown by Fig. 5, the central part of the casing is cored out to provide enlarged cavities sufiicient to accommodate rotation of the eccentrics or cams 22 with adequate clearance.

Since it is an important object of the invention to oppose reciprocation of the pistons with appropriate resistance, each of the cylinders contains a fluid, preferably an incompressible liquid, such as a more or less viscous oil, which will be driven from each cylinder as the piston thereof moves on its compression stroke and will be conducted to another cylinder in which the piston thereof 18 moving in the opposite direction. To this end, the cylinders of each opposed pair are connected by passageways. These include, for each pair of opposed cylinders, a horizontal duct 25, shown in Fig. 3, at each end of the casing, both upper and lower, connected by a lengthwise duct 26. Each of the ducts 25 communicates with one of the cylinder heads and is closed at its outer end by a plug 27 threaded into the casing. Each of the lengthwise ducts 26 is closed by a plug 28 threaded into an end wall of the casing. It will be evident that this arrangement of passages conveys liquid compressed by an outwardly moving piston to the cylinder opposed to it, behind the simultaneously inwardly moving piston. It will also .be evident that resistance offered by this movement of the liquid will be afunction of the viscosity of the liquid and the size of the passageway bore through which it must move. These factors are selected, when manufacturing the device and filling it with liquid, in accordance withdthe service proposed for the device, as will be understoo The shaft 20 projects from one side of the casing as a squared extension 30 for removably receiving a reel or spool 31 having a cable 32 wound thereon with its inner end made fast to the hub of the spool, as shown at 33 and with its outer end terminating in any approved type of separable fastening means such as the snap hook 34 shown in Fig. 1.

A convenient device for making the spool readily aflixed on and removable from the shaft extension 30 is the type of detent 35 shown in Figs. 1 and 7. This consists of a spring pressed ball which yields when flie spool is pushed axially on the extension and snaps out beyond the bore of the spool hub to latch the spool in place whenthe spool has been pushed axially inwardly beyond the ball. With such devices, or its equivalent, the spool can be readily mounted on or removed from the shaft.

Pivoted on the shaft, inwardly of the squared extension and adjacent to the proximate outer wall of the casing, is a cable guide 40, comprising a hub 41 freely swingable 360 around the shaft and an arm 42 extending from the hub and preferably bent outwardly so as to space its free end away from the casing. This free end carries a loop or eye 43 made of heavy wire or light rod stock curled spirally somewhat more than 360 to provide a guide ferrule which is open at one end so that the cable 32 can be quickly inserted, as shown in Figs. 1 and 6.

A metallic pad 45 is mounted on two or more sides of the enlarged center portion of the casing, right angularly or oppositely related to the side of the. casing which carries the guide 40. These pads are all of the same size and form, and they have side edge flanges 4-6 which are removably receivable into the internally open channels 47 formed on the opposite side edges of a bracket plate 48 which may be firmly and permanently bolted or screwed in place at the location where the casingv is to be mounted for use. inner surface of an outside wall of av building, close to a window, or it may be the inside surface of the window frame. It may also be a stanchion or bulkhead on shipboard or the free end of a davit.

Additional supporting means for the casing may be provided in the form of the generally U-shaped bail 50 shown in Fig. l as a portion of substitute means for two of the bolts 13 which secure the casing halves 11 and 12 together. This device may take the form of heavy rod stock bent into the U-shaped form shown, provided. with enlargements 51 for serving as caps or bolt heads, and. threaded at its extreme outer ends for receiving nuts 52. The bight of the bail extends sufiiciently above the upper end of the casing, to which it may be held by a clip 53 welded to the casing side wall, to provide a very convenient type of hook by which the device may be slung from any con venient projection, such as the terminal end of a bed post, a radiator valve or handle, a door knob, or any other fixture of a conventional room or its furnishings over which the bail can be fitted.

The form of device shown in. Figs. l-7 contains no means for adjusting the rate of flow of liquid through the passageways and ducts. It is assumed that this type of the device is made with a bore of predetermined cross sectional size for aflfording sufficient resistance. to the weights intended to be lowered by the device. I have found by actual use that when the device isemployed to lower a person from an upper story of a building, a bore size properly selected with relation to the viscosity of the liquid fill will lower a child weighing less than. 100 pounds other objects of very greatly varying weights are. to be lowered, it is desirable to include in the: device a means for adjusting the bores of the passageways. Such an adjusting means is shown in Fig- 8. It consists; of a passageway drilled. through. theupper half 11 of. the. casing, centrally between the two upper cylinders 14 so as to tap and connect the two lengthwise ducts 26. The outer ends of this passageway 60 are closed by plugs 61, and the passageway between the two ducts 26 is filled by a pair of plungers 62 normally held retracted to seat inwardly against each other by a spring clip 63 having each of its ends anchored in one of the plungers. The plungers are so proportioned that when they are: intheir normal, retracted position, they substantially clear the. ducts 26, leavingthebores thereof wide open.

In order to project the plungers into the bores 26 so as to constrict them equally, a headed stem 65 projects from the upper end wall of the upper half 10 of the casing 11 and is arranged for adjustable positioning by being screwthreaded into the casing end wall, as shown at 66. The inner end of the stem is pointed for insertion between the opposed inner ends of the plungers 62-. It will be evident that when the stem is screwed down the plungerswill be projected so as adjustably and equally to constrict.

This location may, by way of. example, be the the bores of the ducts 26, and that when the stem is screwed out the bores will be enlarged because the spring 63 will retract the plungers to the extent permitted by the position of the stem 65.

Thus the resistance olfered to turning of the shaft 20 may be adjusted. If desired or thought necessary, the adjustment may be fixed more or less permanently by adding a locknut (not shown) to the stem 65.

In use as a fire escape, the casing is mounted on a bracket plate 48 permanently alfixed to the inner surface of a building wall adjacent to a window opening, or to the inner surface of a window frame. Or the casing may be hung by means of the bale 50 from any fixed projection in the room. Accessible to the device is located a supply of wound reels 31 and preferably a number of suitable harnesses or skeletonized jackets to which the fasteners 34 may be connected. A person desiring to use the device will don one of the harnesses, connect a fastener 34 thereto, snap onto the shaft projection 3'0 the reel 31 carrying the fastener, and lower himself out the window. His descent will be retarded at a safe rate by the mechanism inside the casing, as will be understood. When the person thus lowered has alighted in safety, the device may be used by another person in the same way. The second and all succeeding persons will simply apply other fully wound reels to the shaft projection.

It will be recognized that the cable guide 40, when the cable 32 is threaded through the eye 43 thereof, will serve to keep the cable trained properly from the reel or spool regardless of the angle at which the device may be mounted relatively to the straight line of descent.

As has been explained, the springs 17 may or may not be included. They are preferred because they keep the pistons constantly engaged with the eccentrics 22 and thus prevent objectionable piston slap, and also because they increase the resistance to movement of the pistons. The springs are all of equal size and force, thus tending normally to thrust the pistons inwardly to anequal degree. However, resistance to compression of each spring increases with the degree of compression, so that the spring in the upper cylinder 14 of Fig. 5 is overbalancing the spring in the lower cylinder 15. Thus use of the springs adds to the resistance to movement of the pistons, permits the use of liquid of less viscosity and/or use of passageways and ducts of larger bore, and decreases the pressure on the liquid and the resulting tendency of the liquid to leak.

Various changes may be made in the details herein described, and not all of the structural features and elements need be used in combination.

I- claim:

1. A safety lowering device comprising a pair of hollow casing halves each closed at its outer end and open at its inner end and each having a hollow cylinder formed therein, means securing the inner ends together and positioning the cylinders in axial alignment and opposed relationship including a pair of bolt members having their upper ends connected together to provide a bail for hanging the device, pistons reciprocable in the cylinders, a shaft projecting from the casing and having a reel mounted thereon, a cable wound on the reel for rotating the shaft as the cable is unwound, and means driving the pistons in reciprocating movement as the shaft rotates. I

2. A safety device comprising a casing having a hollow interior providing two side by side pairs of cylinders, the cylinders of each pair being opposed and axially aligned and having their head ends remote from each other and connected by a passageway including a bore in the casing paralleling the axis of the connected cylinders, a piston in each cylinder, a liquid fill confined to each passageway and the portion of each cylinder connected thereby between its head end and piston, a shaft extending transversely through the middle portion of the casing and having an end portion projecting from the casing, a pair of eccentrics within the casing mounted on the shaft and bearing respectively on the pistons of each pair for reciprocating them responsive to rotation of the shaft to force the liquid fill through the passageways, a reel having a cable wound thereon mounted on the projecting portion of the shaft, a valve mounted in each passageway, and common operating means accessible from outsidethe casing for regulating simultaneously both valves to adjust the flow of liquid through both passageways.

References Cited in the file of this patent UNITED STATES PATENTS Barlow Mar. 8, 1881 Noack Sept. 17, 1889 Buckelew Apr. 9, 1895 

